Solution 2

Verify that new alerts work. To do this, create a new alert on a test library or on a test list. Perform an action to generate the alert. For example, add, edit, or delete an item. Then, wait 15 minutes. If the alert isn't received, collect the following information, and then contact Microsoft Office 365 technical support:

- Verify the last known time that alerts were received.
- Record the exact steps to reproduce the issue in the new alert.

Solution 3

If the new alert is received but existing alerts aren't received, delete and then re-create all the user's alerts on the site. To do this, see Manage, view, or delete SharePoint alerts to recreate the alert.

Solution 4

If all alerts from multiple files or libraries are not delivered, visit the Service Health Dashboard from the Microsoft 365 admin center, Health, Service health to check for any advisories/incidents that may be occurring with SharePoint or Exchange. The issue could be with the SharePoint alert capability or delays in emails through Exchange. It will also be important to note whether other email is being delivered, and if not, the issue is likely with Exchange delays.

It is not possible to send alerts to Distribution or O365 groups. Only mail-enabled security groups are supported.

You cannot customize alert email templates; you need to use Microsoft FLOW or SharePoint Designer Workflow to achieve those.

More information

This issue may occur if permissions aren't granted to the user's account in order to access the sites, the library, or the list in which the user wants to use alert functionality. This means that users must have permissions to the list or to the library for alerts and to the task list for tasks and for workflows.